Proiect RF2 Ibanescu Victor

8/3/2019 Proiect RF2 Ibanescu Victor

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U.T.C.-N R.F 2 - PROJECT

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Contents

1. The analyses of fitting performance of the initial product..................................................................... 2

1.1 Project requests............................................................................................................................. 2

1.2 The initial product sketch.............................................................................................................. 2

1.3 The initial product structure .......................................................................................................... 4

1.4 The application of DFAFD for the initial product .......................................................................... 5

1.5 The list of weak points of the initial product and the priority of interventions ................................ 6

2. Development the final version of the product........................................................................................ 6

2.1 The improved version of the product ............................................................................................. 6

2.2 The final product structure ............................................................................................................ 7

2.3 The application of DFAFD for the initial product .......................................................................... 8

3. The robotic cell concept ....................................................................................................................... 9

3.1 General presentation ..................................................................................................................... 9

3.2 Robotic cell detailed description ................................................................................................. 10

4. The economic evaluation of the robotic cell ........................................................................................ 11

4.1 Summarizing table of the necessary equipment ........................................................................... 11

4.2 Economic justification of the robotic assembly system solution................................................... 11

5. Ladder diagram for controlling the process ......................................................................................... 13

5.1 List table for inputs outputs ......................................................................................................... 13

6. Conclusions........................................................................................................................................ 16

7. Bibliography ...................................................................................................................................... 17

8. Annexes ............................................................................................................................................. 17


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1. The analyses of fitting performance of the initial product

1.1 Project requests

For this project we have to improve a signal lamp used in mines and in other harsh

environments. We also have to build a robotic cell where we can assembly the lamp faster and more

productive in economic terms, because now our product is made in a normal factory without robots.

There is also an economical challenge to try to produce a product faster and cheaper than the

initial one, for that we have to do economical study and production study.

Assembly represents an important step in the whole production process because this

operational activity is responsible for an important part of the total production costs and the

throughput time. It is one of the most labor-intensive sectors in which the share of the costs could

be 2575% of the total production cost. Practice has proved that the share of the labor cost in the

assembly, in relation to the total production costs, are around 45% for car engines, 55% for

machine-tools, 65% for electrical apparatus. This is because the automation within the

manufacturing process is larger by far than in the case of assembly process.

For the analysis and redesign of the product and the related assembly process will be

presented a concept called DFAFD (design for assembly function deployment) proposed by

Rompesad in 1993. Mainly, this method aims to force the designer to think comprehensively about

the product and process design before proceeding to the development of the assembly system.

1.2 The initial product sketch

The initial product (fig 1.1) is made of:

a) Top lid;b) Bottom lid;c) 3 screws;d) Gasket;e) Electrical module;


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Fig 1.1 The initial product

The dimensions of the lamp are presented in the table 1.1

A B C D E

64 mm 49.8 mm 5 mm 30.5 mm 68 mm

Table 1.1

Where: A top lid diameter;

B top lid height;

C top lid flange height;

D bottom lid height;

E bottom lid diameter;


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1.3 The initial product structure

The interdependencies diagram of component parts for the initial product is presented in

fig 1.2

Fig 1.2

The inter-relations structure of component parts for the initial product is presented in fig 1.3

Fig 1.3

Lamp

Electronic ModuleLid

Screws Lid

Body

Base Gasket

Electronic Module

Body

BaseGasket

Lid Screws

Lid


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The sketch of assembly process for initial product is presented in fig 1.4

Fig 1.4

1.4 The application of DFAFD for the initial product

For the analysis of the initial product and the assembly process will be use the DFAFD

method. The result of the DFAFD is presented in table 1.21.

Table 1.2 [ Snapshot from Excel 2010]

1For complete DFAFD table check Annex 1

Base Electronic

module

LidScrews

Gasket

Gripper a Gripper 3Gripper 1Gripper 1 Gripper 2

Acceptable

Defective

gripper

exchange


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1.5 The list of weak points of the initial product and the priority of interventions

The weak points and the priority of interventions are presented in the table 1.3

Weakness points Interventions

Gasket It will be directly cast in the bottom lid

Screws It will be removed

Top lid It will be redesign

Table 1.3

The gasket is a weak point because is hard for a robot to mount it on the bottom lid so for

that it must be somehow eliminated or replaced with something else. We have to keep in mind that

the lamp will be used in mine where water infiltration and other impurities are often met. From the

DFAFD table we can see at Stiffness section the difficulty for flexible is 4 which is not good for our

percentage.

The screws are also very hard to mount for a robot so we have to eliminate them and for that

the top lid must be redesign. Also we can see that in the DFAFD table at section Joining method the

difficulty forScrewing or adhesive bonding is 4 which will lead to a higher percentage of difficulty

and because a screw can only be screwed we must eliminate them.

2. Development the final version of the product

2.1 The improved version of the product

At the previously chapter we highlights the weakness points and now we try to solve the

problems. The gasket will be cast in the bottom lid so that the robot wont have to mount it. The

screws will be removed because the mounting is made directly between the top lid and the bottom

one with the aid of 2 clamps (fig 2.1).


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Fig 2.1 [Snapshot from Catia V5R19]

2.2 The final product structure

The interdependencies diagram of component parts for the final product is presented in

fig 2.2

Fig 2.2

The inter-relations structure of component parts for the final product is presented in fig 2.3

Fig 2.3

Lid Electronic Module

Body

Clam s

Top lid

Lamp

Electronic ModuleLid Body


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The sketch of assembly process for final product is presented in fig 2.4

Fig 2.4

2.3 The application of DFAFD for the initial product

After we rethink and redesign the product we made the DFAFD simulation to find out if our

product is better than the previous one. The result is presented in the table 2.12

Table 2.1 [Snapshot from Excel 2010]

2For a complete DFAFD Table Check Annex 2

Electronic

module

Top Lid Body

Gripper 1 Gripper 1 Gripper 1


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If we compare the Table 1.2 with Table 2.1 we can see an improvement between the 2 lamps

from 57.52% to 63.25% is not a big difference at first sight but after all economic calculations the

second product is cheaper and more easier to produce which leads to a bigger profit.

3. The robotic cell concept

3.1 General presentation

The robotic cell (fig 3.1) that we create for assembly the lamp is made from:

a) 1SCARA robot Adept 2.1b) 4 conveyors Dorner 22003c) 1 index table from FIBROTOR4d) 1 vacuum gripper from SCHUNK5

Fig 3.1 [Snapshot from Catia V5R19]

3The Dorner Catalogue is presented in Annex 3

4The Fibrotor Catalogue is presented in Annex 4

5The Schunk Catalogue is presented in Annex 5

d

a

b

c


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3.2 Robotic cell detailed description

The 3 conveyors are feed by a worker. This will place the parts for each conveyor until they

are fully occupied. The parts will be carefully placed between the two red lines.

After the conveyors are completed with parts the assembly process is started. The parts will

go towards the index table which has a color-detection sensor which will detect the red line in front

of them. When the red line comes into the range of the sensor this will send a signal to stop the

conveyors. The index table contains 3 slots supporting the parts and in the initial state the slots are

directed towards the conveyors.

The actual assembly will take place as follows: the table rotated until the electric module is

under the gripper. The robot pick the electric module and keep it suspended until the bottom lid is

under the gripper than place the electric module on the lid. The final step in the assembly process is

putting the top lid over the two parts that are already assembled.

After all the parts are put together the robot takes the final product and move it on the final

conveyor which transport the lamp to palletizing station.

When the assembly process is finished the index table returns to the initial state and send a

signal that will starts the conveyors. We also have a sensor that counts how many parts are on the

conveyor and when there remain only two a signal will trigger which will announce the worker that

the conveyors must be feed.


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4. The economic evaluation of the robotic cell

4.1 Summarizing table of the necessary equipment

Indicative values for the economic evaluation of robotic assembly cell are presented in

table 4.1.

Crt.

NRComponents Price ()

6

1 Parts Storages 800

2 Conveyor and Command 8.000

3 Index Table 1.500

4 Limitated contactor course 10

5 Proximity sesnor 50

6 PLC 2.000

7 Vacuum gripper 700

8 Inspection system 12.000

9 SCARA Robot 15.000

Table 4.1

4.2 Economic justification of the robotic assembly system solution

Economic profitability of a certain conception-design alternative for a robotic assembly

system it is identified by means of a coefficient called integral productivity IP7.

If IP


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We can see that for a period of10 years at a price of18 RON/ lamp the integral productivity

will be 1.9. Also we want to know if we can absorb the investment in sooner then 10 years. The

results are presented in table 4.2

Number of years Integral productivity (Ip) Lamp price (RON)

10 1.9 18

5 1.6 18

3 1.4 18

1.5 1.0 18

Table 4.2


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Conclusion: if we manage to maintain the product price at 18 RON/ Lamp not only that we

will absorb the investment in 1 year and a half, but we also start to make some profit.

5. Ladder diagram for controlling the process

5.1 List table for inputs outputs

Inputs Addresses Outputs Addresses

1st sensor of the 1

st conveyor X00 1st conveyor Y00

2nd

sensor of the 2nd

conveyor X01 2nd

conveyor Y01

3rd

sensor of the 3rd

conveyor X03 3rd

conveyor Y02

1st

position of the index table X04 4th

conveyor Y03

2

nd

position of the index table X05

1st

subroutine (takes the

electric module) Y04

3rd


ndsubroutine (place the

electric module)Y05

4th


rdsubroutine (takes the top

lid)Y06

Second to last position on the

conveyorX08

4th

subroutine (place the top

lid)Y07

Proximity sensor for 4th

conveyorX09

5th

subroutine (move the final

product)Y17

1st

subroutine of the robot X10 Activate the alarm Y08

2nd

subroutine of the robot X11Move the index table

clockwiseY09

3rd subroutine of the sensor X12Move the index table

counterclockwiseY10

4th

subroutine of the sensor X13 Starting internal contact Y11

5th subroutine of the sensorX14

Product counter Y12

Start button X15 Stop the process Y13

Stop button X16

Alarm stop button X17


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Fig 5.1 Ladder diagram


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6. Conclusions

The purpose of this project was to try to improve a given product. For achieving our goal we

applied the methods learned along entire semester. After we analyses the product and applied

the DFAFD method we design a new and improved product.

What we can conclude is that: if we respect strictly all the steps and analyze correctly the

DFAFD result we can improved the product both technical and economic. Which will lead to a

higher productivity and higher income for our client.


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7. Bibliography

Course support :Robotization of the Assembly Processes Prof.Dr.Ing.Stelian BRAD

8. Annexes

Annex 1: Firs DFAFD

Annex 2: Second DFAFD

Annex 3: The Dorner Catalogue

Annex 4: The Fibrotor Catalogue

Annex 5: The Schunk Catalogue

Proiect RF2 Ibanescu Victor

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